Fix MRT disabling under OpenGL. Thanks to wing64 for noting this error.

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@3518 dfc29bdd-3216-0410-991c-e03cc46cb475

source/Irrlicht/COpenGLDriver.cpp

@@ -3828,7 +3828,7 @@ bool COpenGLDriver::setRenderTarget(video::ITexture* texture, bool clearBackBuff
 
 	if (CurrentTarget==ERT_MULTI_RENDER_TEXTURES)
 	{
-		for (u32 i=0; i<MRTargets.size(); ++i)
+		for (u32 i=1; i<MRTargets.size(); ++i)
 		{
 			if (MRTargets[i].TargetType==ERT_RENDER_TEXTURE)
 			{

tests/mrt.cpp

@@ -63,7 +63,24 @@ static bool testWithDriver(video::E_DRIVER_TYPE driverType)
 		driver->endScene();
 
 		result = takeScreenshotAndCompareAgainstReference(driver, "-mrt.png");
+
+		driver->beginScene (true, true, video::SColor (255, 200, 200, 200));
+		// render
+		device->getSceneManager()->getActiveCamera()->setPosition(core::vector3df(0,5,0));
+		driver->setRenderTarget( gbufferlist );
+		device->getSceneManager()->drawAll();
+		driver->setRenderTarget(0);
+
+		// draw debug rt
+		driver->draw2DImage(gbuffer[0], core::position2d<s32>(0,0));
+		driver->draw2DImage(gbuffer[1], core::position2d<s32>(64,0));
+		driver->draw2DImage(gbuffer[2], core::position2d<s32>(128,0)); 
+
+		driver->endScene();
+
+		result |= takeScreenshotAndCompareAgainstReference(driver, "-mrt2.png");
 	}
+
 	device->closeDevice();
 	device->run();
 	device->drop();